Apparatus for controlling the needle selectors in a circular knitting machine

ABSTRACT

Apparatus for distributing needle selectors in a circular knitting machine having a plurality of movable needles. Each needle is displaced by engagement with an associated selector. A first cam is provided for moving each of its selectors in a predefined path with respect to its associated needle. The first cam is interrupted along its length and a second cam is arranged at the interruption. The second cam is adapted to displace each selector into a second path with respect to its associated needle. The selector is normally biased to move from the first to the second cams. Selectively operable electromagnetic means is also arranged at said interruption, the force generated by said electromagnet means being greater than the bias thus maintaining the selector in said first predefined path.

United States Patent 11 1 [11-] 3,910,070 Uhlir et al. Oct. 7, 1975 [54] APPARATUS FOR CONTROLLING THE 3,733,855 5/1973 Bliss-Hill 66/50 R NEEDLE SELECTORS IN A CIRCULAR 3,771,328 11/1973 Schindelle et al 66/50 R 3,805,555 4/1974 Nuber 66/50 R KNITTING MACHINE 3,812,691 5/1974 Engelfried 66/50 R [75] Inventors: Pavel Uhlir; Ivo Kouklik, both of 3, ,728 6/1974 Er 66/50 R X Trbic czechoslovakia 3,851,500 12/1974 Wolfshagen 66/50 R [73] Assignee: Elitex, Zavody textilniho F N PATENTS OR APPLICATIONS strojirenstvi generalni reditelstvi, 887,941 12/1971 Canada 66/50 R Leberec, Czechoslovakia 1,944,462 3/1971 Germany 66/50 R 22 El d: M 31, 1973 1 1 e ay Primary Examiner-Wm. Carter Reynolds [21] Appl. No.: 365,572

[57] ABSTRACT [30] Forelgn Apphcafion Prionty Data Apparatus for distributing needle selectors in a circu- June 8,1972 Czechoslovakia 3966-72 1 knitting machine having a plurality of movable needles. Each needle is displaced by engagement with [52] U-S. CI R an associated elector. A first cam is p 'gvided for [51] Int. Cl. D04B 15/78 moving each of its selectors in a predefined path with Field of Search 66/50 25, 154 A respect to its associated needle. The first cam is interrupted along its length and a second cam is arranged References Cited at the interruption. The second cam is adapted to dis- UNITED STATES PATENTS place each selector into a second path with respect to 1,927,016 9/1933 Adler et a1 66/25 its associated needle The Sellector is normally biased 3,449,928 6/1969 Schmidt et a1. 66/50 R to move from the first to the second cams. Selectively 3,472,287 10/1969 Ribler 156/75 UX operable electromagnetic means is also arranged at 3,577,749 5/ 1971 Wright.... 66/50 R said interruption, the force generated by said electro- 3,605,448 9/1971 Rib1er..... 66/75 UX magnet means being greater than the bias thus main 3,667,254 6/1972 Paepkew 66/50 R taining the selector in said first predefined path. 3,710,594 l/1973 Bourgeois 66/50 R 3,715,897 2/1973 Hadam 66/75 R 8 Claims, 7 Drawing Figures l 3 t i t US. Patent 0a. 7,1975 Sheet 1 of3 3,910,070

I villi! I I. yllllll'l US. Patent Oct. 7,1975 Sheet 2 of3 3,910,070

US Patent 0a. 7,1975 Sheet 3 of3 3,910,070

i ll n um nnl FIG. 3

APPARATUS FOR CONTROLLING THE NEEDLE SELECTORS IN A CIRCULAR KNITTING MACHINE BACKGROUND OF INVENTION The present invention relates to the selection of needles in a circular knitting machine and in particular to apparatus for distributing the needle selectors in two positions whereby activation of the needles themselves may or may not be obtained.

In known circular knitting machines the needles are placed in an inoperative or operative position with regard to the yarn or knitting feeds by the manipulation of a selector which moves the needle into its desired position. The selector may act directly on the needle or through intermediate and/or auxiliary jacks mounted together with the needle in the needle trick or bed. Recently, the operation of the selector has been accomplished by the use of electromagnetic means by which a force is generated in accordance with a predetermined program so that the needles may be selectively activated to obtain a particularly designed knit work. Various attempts have been made to solve the problem of electromagnetic selection, that is the distribution of the sinkers into its two paths, one of which is the needle selecting path, the other of which is a basic path maintaining the needle normally out of function. Means are known in which the selectors are displaced from the basic path into a selecting position by the means of resilient spring-like elements which are fastened with one of their ends to the associated needle jack and held with the other end in its resilient or biasing state by a permanent magnet. At the point where selection is to be obtained a program controlled electromagnet is mounted so as to be in proximity with the permanent magnet. At the moment at which the jack is situated at the point'of selection the program controlled electromagnet is activated so as to suppress or oppose the magnetic field of the permanent magnet, whereupon the biased resilient element rebounds or retracts. Upon the reboundiing of the resilient element, the contact surface of the selector is caused toengage with the needle jack so as to change the position of the jack within the needle groove or bed in such a manner that the control butt of the jack engages a cam system which lifts the jack into contact with the associated needle, thus lifting the needle into its operative position and selecting its operation at the yarn feed.

A disadvantage of the above described apparatus, as well as those devices heretofore known, requires that upon the application of electromagnetic selection a considerable reconstruction of the normal cam systems of the knitting machines are required. This is a particular problem especially in small diameter knitting machines.

It is the object of the present invention to provide apparatus for needle selection in a circular knitting machine which overcomes the disadvantages and defects of the prior known devices.

The specific objects and advantages of the present invention will be seen from the following description of its preferred embodiment, as well as its modifications as hereinafter set forth.

SUMMARY OF INVENTION According to the present invention apparatus which substantially mitigates the above mentioned disadvantages and is substantially more reliable and simple in its construction and in its application to small diameter knitting machines is obtained by supporting the selectors associated with each of the needles in engagement with a first cam which maintains the selectors in a predefined basic path out of contact with the needles. This first cam is interrupted in a predefined distance along its path and a second cam is arranged at said interruption so as to be engaged by the selector to be displaced by the cam into engagement with the needle. Spring means normally urges the selector against the first cam and from the first cam to the second cam at the point of interruption. At the point of interruption a selectively operable electromagnetic means, of the type commonly in use in circular knitting machines is arranged. On activation of the electromagnet the force generated by the electromagnet is designed to be greater than that of the spring biasing the selector and thus overcomes the bias and maintains the selector moving in its predefined path. As a result of this construction the needle selector is mechanically urged by the action of the resilient element from its first basic path of movement into a second path of movement wherein the needle is actuated but is on the other hand urged by the selective operation of the electromagnetic means to be maintained in its first path. Since the electromagnetic force generated is greater than that of the force of the resilient element an absolute and assured maintenance of the particular selector is obtained.

Preferably, intermediate and/or auxiliary jacks are mounted in conjunction with the needles within the needle grooves or beds of the cylinder and the selector transmits its action to the needle via these jacks. In this manner the basic construction of the knitting machine can be maintained as near to the standard conventional construction as is possible.

Full details of the present invention is set forth in the following description and is shown in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS In the drawings:

FIG. 1 is a partial section V through lines 1-1 of FIG. 4 showing the needle cylinder and jack ring at the point of selection illustrating the construction of the present invention,

FIG. 2 is a view similar to that of FIG. 1 taken along lines 2-2 of FIG. 4 showing the displacement of the selector member into selecting; position,

FIG. 3 is a view similar to FIG. 1 but angularly offset from the point of selection showing the movement of the selector member into engagement with the needle jack,

FIG. 4 is a plan view of a portion of the selector ring and its cam mechanism at the point of selection,

FIG. 5 is an enlarged view showing the details of the selector as employed in FIGS. 1 through 4,

FIG. 6 is a view similar to that of FIG. 4 showing a modified form of selector and cam mechanism,

FIG. 7 is an enlarged detailed view of the selector member employed in FIG. 6.

DESCRIPTION OF INVENTION As seen in FIGS. 1, 2 and 3 a needle cylinder 1 of a generally conventional single cylinder circular knitting machine is provided with needle grooves, tricks, or

beds 2 about its outer circumference. In each of the beds 2 there is arranged a swingable jack 3, a traversing jack 4 and a needle 5. The swingingjack 3 has a shaped inner edge abutting against the bottom of the bed 2 and is mounted by its outer edge on a suspension ring 6 which is fixed to the needle cylinder. All of the swinging jacks are secured against dropping out by a circular coil spring 7 which sits within a notch adjacent its upper edge. The swinging jack 3 is provided with controlling butts 3, which cooperate with a not shown system of control cams whenever electromagnetic selection is suppressed. The traverse jack 4 is also provided with a contoured inner edge and rests with its end on the upper end of the swinging jack 3. The traversing jack 4 is provided with control butts 4, which are controlled by its own system of cams in the same manner as the control butts 3, of the swinging jack 3 but for the purpose of overcoming the selection as may be obtained by the use of the swinging jack 3. The swinging jack 3 comprises an intermediate jack and the traversing jack 4 comprises an auxiliary jack for the needle 5. The upper end of the traversing jack 4 engages the butt end of the needle. When the auxiliary or traversing jack 4 is pivoted in the manner to be described later, its lowermost butt 4, engages with and cooperates with the upper edge of a cam 8 and other cams arranged on a cam housing 9 which is fixedly connected to the upper flange 10 of the machine frame itself.

The needle cylinder 1 is rotatably mounted at its upper end in a bearing 11 which is secured in the upper flange 10 of the knitting machine and at its lower end in a bearing 12 which is located in the lower flange 13 of the machine frame. At the bottom of the needle cylinder a gear wheel 14 is fixedly connected to it by a key 14'. The gear 14 is connected by conventional gear transmission or other means to the central drive mechanism for the knitting machine.

The traversing needle jacks 4 are, on the one hand, shiftable, i.e., slidable to control the needles and, on the other hand, swingable or pivotable to co-operate with the cam system and the jacks 3. The needle jacks 4 are controlled by the jacks 3 which urge their lower ends into the tricks whereby the lowermost of the butts 4, comes into engagement with the cams of the cam system 8, i.e., with the raising cams only. The jack is sunk by the action of a needle which is controlled solely by the stitch (sinker) cams. Other butts 4, serve to abolish the selection caused by the jack 3, which is of importance for knitting a plain fabric, for example in dividing the needles for knitting ofa heel, for a l :1 needle set-up and the like. The upper butts 4, are controlled from cam discs or by means of sliders controlled by the selection drum. When a needle is raised by the jack 4 then the latter is again pushed back by the said needle and a special cam urges the upper end of the jack 4 into its trick so that the jack resumes its initial position. When the jack has not been selected or its selection has been abolished then the jack stays in its lower position without actuating the needle.

The jack 3 is swingable or pivotable only. The butts 3, serve again (when the electromagnetic selection is cut off), similarly as butts 4,, to select the needles for knitting a heel, for a 1:1 needle set-up and the like, and the butts 3, are controlled by the same means, too.

The suspension ring 6, supporting the jacks 3 comprises the inner race ring of the bearing 12. Mounted to this fixed inner race ring by means of screws 15 is an annular carrier 16 to which is mounted by means of screws 17 a selector support ring 18. The selector support ring which is thus mounted for conjoint movement concentric to the path of rotation of the needle cylinder has a plurality of radially disposed grooves 19 aligned as seen in the figure in the plane of an associated jack 3. Located to be reciprocally movable in each of the grooves 19 is a selector member 20. As seen in FIG. 5 each of the selectors 20 is provided with a depending arm 21, a stop butt 22, a selecting extension surface at its upper edge 23 and a rear selecting edge 24 at its radially circumferential outer end and a selecting edge 25 midway along its upper edge, both of which are adapted to be engaged by suitable cam surfaces to move the selector reciprocally within the grooves 19. A longitudinal lower guide surface 26 is provided at its lower surface of the radially circumferential outer end of each selector, behind the butt stop 22. The depending arm 21 passes through an opening in the bottom of its groove 19 and is fastened by a helical tension spring 27 fastened at its opposite end to a circular disc 28 which is mounted by means of screws 29 to a carrier 16. The spring 27 has a component force urging the selector downwardly so that its bottom edge slidably rides along the bottom of the groove 19. A continuous coil spring is mounted in an upwardly extending notch so as to bear down on the upper edge of the selector 20 keeping the selector 20 secure within the groove 19. Mounted exteriorly of the radially outward circumferential ends of the selectors 20 are a pair of circular cams 30 and 31 which are adapted to engage the selecting edge 24 and the guide surface 26 in the manner to be described later. Mounted above the selectors 20 is a third cam 32 which is adapted to engage the selecting edge 25. The circular cams 30 and 31 are fixedly mounted on a carrier ring 33 while the cam 32 is fastened by means of screws 34 to an enlarged carrier plate 35 which is itself fastened to the carrier ring 33 by the screws 36. The carrier ring 33 is arranged on a plurality'of columns which are fastened to the lower flange l3.

Mounted to the carrier ring 33 above the point at which the specific selectors 20 are to be actuated is a retaining plate 38. The retaining plate 38 prevents the selectors 20 from being lifted within the grooves 19 an excessive amount. Above the plate 38 is a housing in which an electromagnetic device 39 is located. The housing containing the electromagnet is secured by means of screws 40 to the carrier ring 38 also. The electromagnet can comprise a soft iron core surrounded by a coil through which a current may be passed. The parameters of the coil and soft iron core are such that when the electromagnet is energized it creates a field force greater than the downward component of the spring 27 on the selector 20. The electromagnet is placed directly above the position of the selecting extension surface 23. As seen in FIG. 4 the cam 31 has a flat upper surface 41 on which the guiding edge 26 of the selector 20 is adapted to normally rest and ride being pulled downwardly on it by the force of the spring 27. The surface 41 lies in a single plane transverse to the axis of rotation of the needle cylinder and thus defines the first path of the selector 20. The cam surface 41 is interrupted, that is the edge of the cam 31 is cut back, stradling the point of selection defined by the electromagnet 39. This predetermined point is indicated by the space defined by double arrow S as seen in FIG. 4; thus cams 30 and 31 are coextensive at this point. Under normal conditions the supporting ring 16 on which the selectors 20 are located will rotate with the needle cylinder 1, so that the guiding edge 26 rides on the surface 41 until it reaches this interrupted portion at which time the force of the spring 27 will pivot the rear end of the selector 20 downwardly as seen in FIG. 2 so that the rear edge 24 will abut against the radially inner edge of the cam 31 as seen in FIG. 3. Once this occurs the further turning of the needle cylinder causes the depressed selector to have its rear edge 24 abut against a contoured cam surface 42 constituting the radially inner edge of the cam 31. As seen in FIG. 4 this contour is such that it has a high surface which on continuous rotation of the selectors in the direction of the arrow S will cause the selectors to move radially in the forward direction toward the needle cylinder 1 in a second path which is displaced with respect to the first path. As it reaches the high point the front end of the selector 20 abuts the radially outer edge of the jack 3, as seen in FIG. 3 causing the jack to pivot radially inwardly about its node so its upper end presses against the lower end of the traversing auxiliary jack 4, as seen in FIG. 3. When this occurs the upper end, that is the butt end of the traversing jack 4 moves outwardly so that the lower butt 4 engages over the edge of the cam 8 fixed about the ring 9. The functioning edge of the cam 8 is such that when this occurs the cam causes the traversing jack 4 to rise having its upper edge engage the needle 5 moving the needle 5 upwardly so that it functions in cooperation with the needle feed to produce the knit function desired.

On the other hand, when it is desired to suppress the operation of the needle 5, the electromagnet 39 is actuated setting up an electromagnetic force which acts in the opposite sense to that of the spring 29. Since as noted before this electromagnetic force is stronger than the downward component of the spring 27 the electromagnet lifts the rear end of the selector 20, as it passes through the space S so that it does not fall into the interruption of the cam 41 and is maintained along its planar circular path defined by the surface of the cam 41 .until it passes over the interruption S and again comes to rest on the surface 41. Thus, by actuation of the electromagnet the selector may be maintained in its first path rather than being forced by action of the spring 27 to descend into its second path of movement.

After the cam edge 42 has pushed the selector member 20 to its most forward position, the cam edge 42 recedes. The forward selecting edge then abuts against the functioning edge of the cam 32 and is begun to be pushed to the rear. At this time the guiding edge 26 of the selector 20 begins to rest on its terminal surface portion 43 which is upwardly inclined and which carries the rear end of the selector 20 vertically upward until it rests on the planar surface 41, once again. At the same time the cam 32 fully returns the selector 20 so that its rear selecting edge 24 again abuts against the circular edge of the circular cam 30. The selectors are carried around with the movement of the needle cylinder 1 until they again come into the area of interruption in the planar cam surface 41.

The electromagnetic device is actuated in known manner by suitable programming means well known in the present art. These programming means can be tape recorded, recorded on cards or in other manner mechanically or magnetically recorded so that a predefined program of operation can be effected by selectively operating the electromagnet 39 with selected needle selectors.

In FIGS. 6 and 7 another embodiment of the selector here numbered 20' is shown in connection with a circular cam 44 which has as its basic operating path the normal reciprocation of the selector 20 into engagement with the jack 3 and in its second path the movement of the selector 20' so that it is taken out of engagement with the jack 3. Thus, the electromagnetic force 39 is provided to lift the specific selector to maintain in its basic path in which it does actuate its associated needle. As seen in FIG. 7 the selector 20 is similar in nature to that shown in the previous embodiment except that its depending finger 21 is directed radially inwardly toward the needle cylinder and is held with the spring 27 to the circular disc 28' so that it has a greater radial component than a downward component. The rear end of the selector 20 is provided with a downwardly depending butt 45 which engages over the rear edges of the circular cam 44.

As seen in FIG. 6 the circular cam 44 has a circumferential outer edge 44 which is generally cylindrical in nature. At the predetermined point of selection, indicated by the opposing arrows S the circumferential edge 44 is notched at 50 in an inwardly directed V- shape. After this point the circumferential edge 44 is contoured as at 47 radially inwardly to a low point from which it then is contoured radially outwardly to return to the circular circumferential edge portion 44. To the rear of the edge 44 the circular cam 44 is stepped so as to form a second cam 46' having a planar surface 46 upon which the bottom surface of the butt 45 is normally adapted to ride. The second cam 46 is connected with the first cam 44 and coextensive with the notch 50 which provides the predetermined point of selection. The V-shaped notch has an edge 50 which extends radially outward to an edge 49 which is substantially concentric with the normally cylindrical cam edge 44 but has a greater diameter. The diameter of the edge 49 cooperates with the inner circumferential edge of the circular cam 44 so .as to permit the selector to reciprocate radially inwardly and outwardly therebetween. Following the edge 49 the planar surface 46 is provided with an upwardly inclined surface 52 which will again carry the depressed selector back up to the planar surface 46. As will be obvious from FIG. 6 the contoured edge 47 permits the spring 27 to draw the selector radially inward so that its frontal edge engages the jack 3 to effect the operation of the needle as afore described. Under normal conditions, however, the selector once it reaches the space S will be caused to fall into the notch and be carried onto the surface edges 50 and 49 maintaining the selector out of engagement with the jack 3. It is only by activation of the electromagnet that the selector is lifted by its extension surface 23 so that it is maintained against the cam surface 44 and 47' so that the actuation of the needle will occur.

The embodiment shown in FIGS. 1 through 5 operates as follows:

The needle cylinder 1 is driven in conventional manner by known driving mechanism via the gear wheel 14 so that it rotates carrying the selector supporting ring 18 conjointly with it in the direction of arrow S, thus carrying the selectors 20 in a continuous path together with its associated needles. The distribution of the selector 20 into one of its two positions is performed as follows. The selectors 20 are retained in their basic predetermined path defined by the cam 30, since their lower guiding edges 26 ride on the planar surface 41 of the circular cam 31 until such time as the selectors reach the interrupted space defined by the double arrows S. At this point of interruption, the distribution of the selectors 20 into the second path takes place automatically in the absence of the activation of the electromagnet 39. The spring 27 has a perpendicular component which pulls the selectors 20 downwardly so that the rear edges 24 abut against the vertical edges of the planar surface 41. The contoured edge 42 then causes the depressed selector to move forwardly into contact with the jack 3 as previously described. The bottom surface 22 riding against the bottom of the groove 19 in which the selectors are supported. On the other hand if it is desired not to actuate any given needle 5 the electromagnet 39 is activated as soon as the associated selector passes beneath it so that the rear end of the selector is lifted and the guiding surface 26 transferred over the interruption defined by the opposing arrows S onto the continuation of the flat planar surface 41.

The operation of the embodiment shown in FIGS. 6 and 7 function in basically the same manner with the one difference in that the selectors 20 do not cooperate in its second position with the jacks 3 so as to actuate the needles 5 but bear against the cam surface 51 and the outer surface 49 so as to be drawn out of engagement with jacks 3. The selectors 20 in their basic or first path of movement would normally be moved into engagement with the jacks 3 except for the fact that they would fall into the interruption created by the space defined by the double arrows S. In this embodiment the electromagnet 39 is activated at predetermined selected times to maintain the selectors in their basic path in which this actuation of the needles 5 occurs. As seen from the forgoing, the present invention combines the mechanical action of a resilient member or spring which continuously biases the selector in one direction with the action of a selectively operable electromagnet which may be used either to move the selector into a second position or to continue it in its basic position. The advantage of the present invention exists in that the selectors may be mounted upon a common selector supporting ring about the exterior of the needle cylinder. Thus, their guage at the point of selection defined by the extension surface 23 may be made sufficiently large so that this surface in cooperation with the electromagnet and the cam may be made sufficiently reliable and insure accurate and perfect performance at all times. The arrangement is furthermore particularly advantageous when used with needle cylinders having a very small diameter. Since the selectors extend radially outward the operating cam, the extension surfaces, etc. may be sufficiently spaced apart since the angular divergence of the selectors with respect to each other permits such enlarged construction. Thus, the present invention can be adapted to very fine hosiery knitting machines. A further advantage consists in that the present invention may be used on machines without restructuring its original mechanical selection devices. This can be obtained merely by removing the conventional patterning drums which act directly onto the needle jacks or intermediate jacks. As a result the present invention may be universally employed. A significant advantage of the present invention consists in the fact that only a negligible change of position in the selector itself, that is very small shifting from one path to the second path results in the actuation of the selector and the associated needle. Thus small degrees of movement and forces are required to obtain the desired results.

The foregoing disclosure and drawings illustrate the present invention by means of only two specific examples. The present invention, however, can be modified and embodied in other structural forms without departing from the scope of the concept of the present invention. For example, the operative traverse of the selectors 20 can be controlled solely with the use of cams and the spring need only be provided to move the selector from the basic movement position to the secondary moving position. Furthermore, the spring need not have a cylindrical shape and the circular single cam acting on the selectors 20 may be replaced by a number of separate independent cams. For example the cam path for holding the selector in its basic position may itself be constituted by a plurality of cams. The selectors 20 as seen in the illustrated embodiments are mounted to reciprocate perpendicularly to the jacks 3. They may if desired be mounted below the jacks 3 or at an angle thereto so that they move more or less vertically with respect to the jacks lifting the jacks into engagement with the traversing jacks 4.

Since various modifications and changes have been suggested it is intended that the scope of the present invention be limited only by the appended claims.

What is claimed:

1. Apparatus for distributing needle selectors in a circular knitting machine having a plurality of movable needles arranged on a rotating needle cylinder, each needle being displaced at a predetermined point along its path of rotation by operation of a jack in engagement with an associated selector, comprising means for supporting said selectors for conjoint movement with said needle cylinder, a first cam for radially directing each of said selectors in a first predefined path with respect to its associated jack and a second cam arranged adjacent said first cam and coextensive therewith at least at the predetermined point for displacing each selector into a second path radially opposite to said first path with respect to its associated jack, said first cam having a predefined contoured path adapted to maintain each of said selectors out of contact with its associated needle jack and being contoured at said predetermined point to permit transfer of said selector to said second cam, said second cam having a contoured path adapted to displace said selector into engagement with its associated needle jack, spring means biasing each selector into engagement with said first cam in a direction to force said selector to normally transfer from said first to said second cam at the predetermined point, and a selectively operable electromagnet arranged at the predetermined point adapted to act on the selectors thereat, the force generated by said electromagnet being greater than the force of said spring means so as to overcome said spring bias and maintain said selector in said first predefined path while passing said predetermined point.

2. The apparatus according to claim 1 wherein each of said needles is arranged in a bed in said needle cylinder, each of the jacks being mounted axially with respect to its associated needle in said bed and arranged intermediate of said needle and said selector to transmit the action of said selector to said needle.

3. The apparatus according to claim 1 wherein each of said selectors has a lower guide surface and a rear edge, the lower guide surface being adapted to ride on the upper surface of said second cam and to be urged in sliding engagement therewith by the action of said spring means, the rear edge of each of said selectors being adapted to engage the edge of said second cam on reaching the predetermined point, said second cam having a contoured surface adapted to move said selector in a direction perpendicular to the biasing component of said spring and said contoured surface to thereafter permit the return of said selector into engagement with said first cam, a third cam arranged to engage said selector and radially move said selector opposite to the direction of movement caused by said second cam into engagement with said first cam on reaching of said last mentioned return surface.

4. Apparatus for distributing needle selectors in a circular knitting machine having a plurality of movable needles arranged on a rotating needle cylinder, each needle being adapted to be operated by an associated jack in selective engagement with an associated selector, comprising a ring fixed to said needle cylinder for conjoint rotation with said needle cylinder, said ring having a plurality of grooves in each of which a selector is slidably mounted, said grooves being arranged to extend radially outward along a diametrical plane with the needle bed, a first cam for moving each of said selectors in a predefined path with respect to its associated jack and a second cam arranged to displace each selector into a second path with respect to its associated jack, said first and second cams being mounted to engage the radially outward circumferentiaal ends of said selectors, spring means normally biasing each selector to force said selector from said first to said sec ond cams and a selectively operable electromagnet arranged at the predetermined point and adapted to act directly on the selector thereat, the force generated by said electromagnet being greater than the force of said spring means so as to overcome said spring bias and maintain said selector in said first predefined path.

5. The apparatus according to claim 4 wherein said first cam has a predefined contoured path adapted to maintain said selector in engagement with its associated needle jack and said second cam has a contoured path adapted to displace said selector out of engagement with the associated needle jack.

6. The apparatus according to claim 5, wherein each of said selectors has a depending butt at its rear end and said first cam comprises a circular ring over which said butt extends, said spring means urging said butt against the circumferential edge of said ring, said circumferential edge forming a contoured surface adapted to permit said spring to displace said selector into engagement with the associated needle jack at a contoured edge, said second-cam having a circumferential edge causing the displaacement of said selector away from the needle jack, and an initial surface portion causing said selector to move from the predetermined point onto said circumferential edge and a terminal surface portion returning said selector from said circumferential edge to said contoured surface of said first cam.

7. The apparatus according to claim 4 wherein said selector has a lower edge and said spring means comprises a tension spring connected at one end to the lower edge of said selector and at its other end to a radially extending disc arranged below said selector ring and fixed to said needle cylinder to rotate conjointly therewith.

8. The apparatus according to claim 4 wherein each of said needles is arranged in a bed in said needle cylinder, each of the jacks being mounted axially with respect to its associated needle in said bed and arranged intermediate of said needle and said selector to transmit the action of said selector to said needle.

* =l l =l 

1. Apparatus For distributing needle selectors in a circular knitting machine having a plurality of movable needles arranged on a rotating needle cylinder, each needle being displaced at a predetermined point along its path of rotation by operation of a jack in engagement with an associated selector, comprising means for supporting said selectors for conjoint movement with said needle cylinder, a first cam for radially directing each of said selectors in a first predefined path with respect to its associated jack and a second cam arranged adjacent said first cam and coextensive therewith at least at the predetermined point for displacing each selector into a second path radially opposite to said first path with respect to its associated jack, said first cam having a predefined contoured path adapted to maintain each of said selectors out of contact with its associated needle jack and being contoured at said predetermined point to permit transfer of said selector to said second cam, said second cam having a contoured path adapted to displace said selector into engagement with its associated needle jack, spring means biasing each selector into engagement with said first cam in a direction to force said selector to normally transfer from said first to said second cam at the predetermined point, and a selectively operable electromagnet arranged at the predetermined point adapted to act on the selectors thereat, the force generated by said electromagnet being greater than the force of said spring means so as to overcome said spring bias and maintain said selector in said first predefined path while passing said predetermined point.
 2. The apparatus according to claim 1 wherein each of said needles is arranged in a bed in said needle cylinder, each of the jacks being mounted axially with respect to its associated needle in said bed and arranged intermediate of said needle and said selector to transmit the action of said selector to said needle.
 3. The apparatus according to claim 1 wherein each of said selectors has a lower guide surface and a rear edge, the lower guide surface being adapted to ride on the upper surface of said second cam and to be urged in sliding engagement therewith by the action of said spring means, the rear edge of each of said selectors being adapted to engage the edge of said second cam on reaching the predetermined point, said second cam having a contoured surface adapted to move said selector in a direction perpendicular to the biasing component of said spring and said contoured surface to thereafter permit the return of said selector into engagement with said first cam, a third cam arranged to engage said selector and radially move said selector opposite to the direction of movement caused by said second cam into engagement with said first cam on reaching of said last mentioned return surface.
 4. Apparatus for distributing needle selectors in a circular knitting machine having a plurality of movable needles arranged on a rotating needle cylinder, each needle being adapted to be operated by an associated jack in selective engagement with an associated selector, comprising a ring fixed to said needle cylinder for conjoint rotation with said needle cylinder, said ring having a plurality of grooves in each of which a selector is slidably mounted, said grooves being arranged to extend radially outward along a diametrical plane with the needle bed, a first cam for moving each of said selectors in a predefined path with respect to its associated jack and a second cam arranged to displace each selector into a second path with respect to its associated jack, said first and second cams being mounted to engage the radially outward circumferentiaal ends of said selectors, spring means normally biasing each selector to force said selector from said first to said second cams and a selectively operable electromagnet arranged at the predetermined point and adapted to act directly on the selector thereat, the force generated by said electromagnet being greater than the forcE of said spring means so as to overcome said spring bias and maintain said selector in said first predefined path.
 5. The apparatus according to claim 4 wherein said first cam has a predefined contoured path adapted to maintain said selector in engagement with its associated needle jack and said second cam has a contoured path adapted to displace said selector out of engagement with the associated needle jack.
 6. The apparatus according to claim 5, wherein each of said selectors has a depending butt at its rear end and said first cam comprises a circular ring over which said butt extends, said spring means urging said butt against the circumferential edge of said ring, said circumferential edge forming a contoured surface adapted to permit said spring to displace said selector into engagement with the associated needle jack at a contoured edge, said second cam having a circumferential edge causing the displaacement of said selector away from the needle jack, and an initial surface portion causing said selector to move from the predetermined point onto said circumferential edge and a terminal surface portion returning said selector from said circumferential edge to said contoured surface of said first cam.
 7. The apparatus according to claim 4 wherein said selector has a lower edge and said spring means comprises a tension spring connected at one end to the lower edge of said selector and at its other end to a radially extending disc arranged below said selector ring and fixed to said needle cylinder to rotate conjointly therewith.
 8. The apparatus according to claim 4 wherein each of said needles is arranged in a bed in said needle cylinder, each of the jacks being mounted axially with respect to its associated needle in said bed and arranged intermediate of said needle and said selector to transmit the action of said selector to said needle. 